Efforts have been made in the past to utilize suction in addition to the more conventional methods for stripping the flats of a textile carding machine. For example, British Pat. No. 148,614 of July 22, 1920 illustrates the use of two tubes or shells, one arranged within the other, the inner shell being a suction conduit having circumferentially spaced slots which are successively exposed to a slotted opening within the outside shell to concentrate the force of the suction. In this patent, the suction is concentrated between the carding surface of the main cylinder and the doffer. The difficulty with this sort of arrangement is that lint, trash and the like accumulates between the relatively rotating shells making for inefficiency in operation, damage to the parts, as well as the necessity for excessive cleaning and maintenance. Another similar device is shown operating in connection with the flats in French Pat. No. 548.777 of Jan. 25, 1923. U.S. Pat. No. 3,604,061 illustrates the use of a more conventional brush positioned adjacent the forward end of conventional flats over the doffer. In this instance, a plenum arrangement is also employed to collect flat strips dislodged by the brush.
Various flat arrangements have been employed in the past in addition to the conventional wherein one set of flats turns relatively slow in a direction opposed to the direction of rotation of the main cylinder. Variations include the use of two sets of flats as, for example, where a first set of flats extends from adjacent the lickerin over a portion of the main cylinder to a point where a second and usually more extensive set of flats fills out the remaining area normally occupied by a conventional flat system.
Accordingly, it is an important object of this invention to provide an improved suction apparatus for cleaning carding surfaces which is especially useful in connection with stripping card flats.
Another important object of the invention is to provide an improved flat stripping apparatus which will require a minimum of maintenance and which will itself require cleaning less often.
Another important object of the invention is to provide an improved flat stripper wherein suction forces are concentrated and wherein fouling as a result of line and flat strip accumulations is minimized.